A new U.S. Geological Survey
study, using data collected
at national wildlife refuges
and other sites, finds a steep drop
in the numbers of frogs, toads and
salamanders across the country. The
study shows widespread species
declines even in protected areas such
as refuges.

On average, amphibian populations
studied vanished from habitats at a
rate of 3.7 percent each year. At that
rate, these species would disappear
from half of their current habitats
in about 20 years. Morethreatened
species disappeared from their
studied habitats at a rate of 11.6
percent each year. At that rate, these
species would disappear from half
of their current habitats in about
six years.

Amphibians have been a constant
presence in our planets ponds, streams,
lakes and rivers for 350 million years
or so, surviving countless changes that
caused many other groups of animals
to go extinct, said USGS Director
Suzette Kimball. This is why the
findings of this study are so noteworthy;
they demonstrate that the pressures
amphibians now face exceed the ability of
many of these survivors to cope.

The study found declines even in
species presumed to be relatively
stable and widespread. Declines were
documented nationwide, from the
swamps in Louisiana and Florida to
the high mountains of the Sierras and
the Rockies.

Even though these declines seem
small on the surface, they are not, said
USGS ecologist Michael Adams, the lead
author of the study. Small numbers
build up to dramatic declines with time.
We knew there was a big problem with
amphibians, but these numbers are both
surprising and of significant concern.

The study did not evaluate causes of
decline, but researchers speculated
disease and climate warming were
among contributing factors. The decline
in amphibian numbers affects humans
because amphibians control pests,
provide medicines, feed other animals
and help make ecosystems work.

The studyreportedly the first to
measure the rate at which amphibians are
disappearingwas published in the
journal PLOS ONE:
http://bit.ly/13LZcRu.